The proposed research is a continuation of previous work on hemoglobins, catalase, and lactoperoxidase. Previous precise chemical investigation of the G gamma and A gamma chains of human hemoglobin F which are the products of non-allelic structural genes has yielded much information about the status of these genes in various hematological abnormalities and about the control and production of the gamma chains. It is proposed to continue the still incomplete investigation of the T gamma chains which contain a second difference in sequence and to correlate the results with known data from G gamma and A gamma chains. It is proposed to collaborate with Dr. Joseph DeSimone of the University of Illinois College of Medicine to study the nature of the induction of Hb-F in the adult baboon. This information should be relevant to hemoglobin switching in humans. Preliminary studies of peptide separations by high performance liquid chromatography (HPLC) would be continued and applied to these and other problems of protein chemistry. It is proposed also to modify bovine liver catalase with various reagents to learn more about structure and function. Experiments with lactoperoxidase would emphasize the determination of sequence.